• Journal of Trauma and Injury
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• 제23권2호
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• pp.175-179
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• 2010

Purpose: Sternal fractures after blunt thoracic trauma can cause significant pain and disability. They are relatively uncommon as a result of direct trauma to the sternum and open reduction is reserved for those with debilitating pain and fracture displacement. We reviewed consecutive 11 cases of open reduction and fixation of sternum and tried to find standard approach to the traumatic sternal fractures with severe displacement. Methods: From December 2008 to August 2010, the medical records of 11 patients who underwent surgical reduction and fixation of sternum for sternal fractures with severe displacement were reviewed. We investigated patients' characteristics, chest trauma, associated other injuries, type of open reduction and fixation, combined operations, preoerative ventilator support and postoperative complications. Results: The mean patient age was 59.3years (range, 41~79). The group comprised 6 male and 5 female subjects. Among 11 patients who underwent open reduction and fixation for sternal fracture with severe displacement, 6 cases had isolated sternal fractures and the other 5 patients had associated other injuries. Sternal fractures were caused by car accidents (9/11, 81.8%), falling down (1/11, 9.1%) and direct blunt trauma to the sternum (1/11, 9.1%), respectively. 3 of the 7 patients (42.9%) who underwent sternal plating with longitudinal plates showed loosening of fixation. Otherwise, none of the 4 patients who underwent surgical fixation using T-shaped plate had stable alignment of the fracture. Conclusion: Sternal fractures with severe displacement need to be repaired to prevent chronic pain, instability of the anterior chest wall, deformity of the sternum, and even kyphosis. In the present study, a T-shaped plate with a compression-tension mechanism constitutes the treatment of choice for displaced sternal fractures.

• 동의생리병리학회지
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• 제19권4호
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• pp.903-907
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• 2005

Many naturally occurring plant extracts are studied for their beneficial effects for health and particularly on cancer. Apoptosis, or programmed cell death, occurs in both normal and pathological conditions, including cancer Dysregulation of apoptosis allows transformed cells to continually and uninhibitedly enter the cell cycle, thus perpetuating the sequence of mutation, genomic instability and, finally, oncogenesis. To investigate the apoptosis-inducing effect of the extract of Fructus Trichosanthis (EFT) on leukemic HL-60 cells and its mechanism, HL-60 cells in vitro in culture medium were given different doses of the extract. The inhibitory rate of cells were measured by microculture tetrazolium assay, cell apoptotic rate was detected by flow cytometry, morphology of cell apoptosis was observed by DAPI fluorescence staining, and the activations of caspases and PARP were detected using Western blotting analysis. The extract could activate the caspase-3 and caspase-8, induce PARP cleavage, inhibit growth of HL-60 cells, and cause apoptosis significantly The suppression was in dose-dependent manner. Marked morphological changes of cell apoptosis including condensation of chromatin and nuclear fragmentation were observed clearly by DAPI fluorescence staining especially. These results will provide strong laboratory evidence of EFT for clinical treatment of acute leukemia.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2018년도 춘계학술대회 논문집
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• pp.55-55
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• 2018

Recently, amorphous oxides such as InGaZnO (IGZO) and InZnO (IZO) as a channel layer of an oxide TFT have been attracted by advantages such as high mobility, good uniformity, and high transparency. In order to apply such an amorphous oxide TFTs to a display, the stability in various environments must be ensured. In the InGaZnO which has been studied in the past, Ga elements act as a suppressor of oxygen vacancy and result in a decreased mobility at the same time. Previous studies have been showed that the InZnO, which does not contain Ga, can achieve high mobility, but has relatively poor stability under various instability environments. In this study, the TFTs using $IZO/Al_2O_3$ double layer structure were studied. The introduction of an $Al_2O_3$ interlayer between source/drain and channel causes superior electrical characteristics and electrical stability as well as reduced contact resistance with optimally perfect ohmic contact. For the IZO and $Al_2O_3$ bilayer structures, the IZO 30nm IZO channels were prepared at $Ar:O_2=30:1$ by sputtering and the $Al_2O_3$ interlayer were depostied with various thickness by ALD at $150^{\circ}C$. The optimal sample exhibits considerably good TFT performance with $V_{th}$ of -3.3V and field effect mobility of $19.25cm^2/Vs$, and reduced $V_{th}$ shift under positive bias stress stability, compared to conventional IZO TFT. The enhanced TFT performances are closely related to the nice ohmic contact properties coming from the defect passivation of the IZO surface inducing charge traps, and we will provide the detail mechanism and model via electrical analysis and transmission line method.

• 한국항공우주학회지
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• 제43권9호
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• pp.838-844
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• 2015

본 논문은 고체 로켓 모터 연소실 내의 연소과정 중 발생하는 연소 불안정 현상을 억제하는 여러 요소들 중 입자에 의한 감쇠와 유동방향 변환 감쇠에 대한 선행연구의 연구결과를 정리 분석하였다. 입자에 의한 감쇠는 연소실 내에서 발생하는 고주파 연소불안정을 억제하는데 있어 가장 효과적이며 입자의 직경과 질량 분율에 영향을 받는다. 한편 입자에 의한 감쇠에 비해 적은 감쇠량을 갖는 유동방향 변환 감쇠는 추진제의 구조에 따라 변하며, 추진제 표면에서 생성된 와도를 고려한다면 펌핑에 의한 증폭을 고려해야한다. 그러나 추진제의 형상이 원통형일 경우 유동방향 변환 감쇠와 펌핑에 의한 증폭의 크기는 같아지고 상쇄가 일어나 연소 안정성을 보다 쉽게 평가할 수 있다.

• 대한한의학회지
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• 제18권1호
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• pp.25-39
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• 1997

Shoulder hand syndrome is characterized by pain, vasomotor instability, and tenderness, mainly in the distal upper extremity. The pathophysiologic mechanism of this syndrome is not yet proved. The purpose of this study is to evaluate the usefulness of thermographic imaging on shoulder hand syndrome after stroke for early diagnosis and its clinical pattern analysis including acupuncture and electroacupuncture therapy. This study was performed from June to September in 1996 on 46 stroke patients who were admitted at Oriental hospital of Kyung Hee Medical Center. The study group were 23 patients with shoulder hand syndrome. The control group were 23 patients without shoulder hand syndrome. Skin temperatures on the both upper extremities were measured by Digital Infrared Thermographic Imaging(D.I.T.I.) before the study and 3 weeks later again. The results were as follows; 1. The shoulder hand syndrome group were significantly more restricted in shoulder passive range of motion than the control group. 2. The shoulder hand syndrome group showed significant temperature difference of both dorsal hands. 3. The electroacupunture therapy group were significantly more improved on the temperature difference of both dorsal hands than acupuncture therapy group in 3 weeks later. 4. Both posterior arms showed the biggest temperature difference from 11 to 30 days in shoulder hand syndrome group. 5. The lesser passive ROM(range of motion) of shoulder group showed significantly increased temperature difference of both hands. The above results show that measurement of shoulder passive range of motion and D.I.T.I. is a useful method for early diagnosis on shoulder hand syndrome and its clinical pattern analysis including evaluation of acupuncture and electroacupuncture therapy. Continuous study will be needed for more clinical application and evaluation on shoulder hand syndrome.

• 대기
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• 제26권1호
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• pp.159-183
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• 2016

On 31 July 2014, there was a localized torrential rainfall ($58.5mm\;hr^{-1}$) caused by a strong convective cell with thunder showers over Daegwallyeong. In the surface synoptic chart, a typhoon was positioned in the East China Sea and the subtropical high was expanded to the Korean peninsula. A WRF (Weather Research and Forecasting) numerical simulation with a resolution of 1 km was performed for a detailed analysis. The simulation result showed a similar pattern in a reflectivity distribution particularly over the Gangwon-do region, compared with the radar reflectivity. According to the results of the WRF simulation, the process and mechanism of the localized heavy rainfall over Daegwallyeong are as follows: (1) a convective instability over the middle part of the Korean peninsula was enhanced due to the low level advection of warm and humid air from the North Pacific high. (2) There was easterly flow from the coast to the mountainous regions around Daegwallyeong, which was generated by the differential heating of the insolation among Daegwallyeong and the Yeongdong coastal plain, and nearby coastal waters. (3) In addition, westerly flow from the western part of Daegwallyeong caused a strong convergence in this region, generating a strong upward motion combined by an orographic effect. (4) This brought about a new convective cell over Daegwallyeong. And this cell was more developed by the outflow from another thunderstorm cell to the south, and finally these two cells were merged to develop as a strong convective cell with thunder showers, leading to the record breaking maximum rainfall per hour ($58.5mm\;hr^{-1}$) in July.

• 한국통신학회논문지
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• 제35권1A호
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• pp.80-86
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• 2010

본 논문은 게이트 채널 길이 0.13 [${\mu}m$]의 p-MOS 트랜지스터에서 음 바이어스 온도 불안정(NBTI) 전류 스트레스 인가에 의한 게이트유기 드레인 누설(GIDL) 전류를 측정 분석하였다. NBTI 스트레스에 의한 문턱전압의 변화와 문턱전압아래 기울기와 드레인 전류 사이에 상관관계로부터, 소자의 특성 변화의 결과로 열화에 대한 중요한 메카니즘이 계면 상태의 생성과 관련이 있다는 것을 분석하였다. GIDL 전류의 측정 결과로부터, NBTI 스트레스에 기인한 계면상태에서 전자-정공 쌍의 생성이 GIDL 전류의 증가의 결과를 도출하였다. 이런 결과로 부터, 초박막 게이트 산화막 소자에서 NBTI 스트레스 후에 증가된 GIDL 전류를 고려해야만 한다. 또한, 동시에 신뢰성 특성과 직류 소자 성능의 고려가 나노 크기의 CMOS 통신회로 설계의 스트레스 파라미터들에서 반드시 있어야 한다.

• 전자공학회논문지SC
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• 제48권4호
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• pp.33-39
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• 2011

이족로봇은 높은 자유도로 인하여 기구적인 불안정성을 내포하고 있기 때문에 보행 시 자세 안정성의 확보가 중요하다. 일반적으로 평지에서는 안정적인 정적 보행이 가능하지만 평지가 아닌 비평탄 지형에서는 보행의 안정성이 현저하게 떨어진다. 본 논문에서는 비평탄 지형에서 이족로봇의 자세 안정화를 포함한 강인한 보행 방법을 제안하였다. 이족로봇의 중앙에 장착된 자이로 센서와 가속도 센서 값을 기반으로 보행 순간마다 센서 값을 감지하여 로봇 몸체의 기울어진 각도를 인식하여 보행 자세를 안정화하는 강인 보행 알고리즘을 설계하였다. 비평탄 지형 보행은 로봇의 기울어진 각도를 인식하여 그 상황에 맞게 관절 각도를 변화시켜 이족로봇 상체의 각도가 평지보행에서와 같도록 하체관절의 각도를 보정하여 보행에서의 안정성을 높였다. 제안된 보행알고리즘은 실제 제작된 이족로봇을 사용하여 비평탄 지형에서 실험하여 제안된 보행 알고리즘의 성능을 검증하였다.

• 한국세라믹학회지
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• 제47권5호
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• pp.401-406
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• 2010

For the lower-temperature preparation of calcium monoaluminate(CA, C:CaO, A:$Al_2O_3$) clinker which is hard to synthesize purely within its melting point, an equimolar hydrate was obtained and then used as a starting raw material of clinker burning. The hydrate was prepared from a mixture of waste oyster shell and industrial aluminium hydroxide by heating to $1200^{\circ}C$, grinding and mixing with water. The hydrate was composed of amorphous aluminium hydroxide and $C_3AH_6$(H:$H_2O$) formed by resolution-precipitation mechanism of the system C-A-H. By heating the hydrate, nearly pure and porous calcium monoaluminate clinker was formed at $1400^{\circ}C$ which is fairly lower temperature than that of its melting point. The formation of calcium monoaluminate was performed mainly by the reaction between amorphous alumina and $C_{12}A_7$ caused by the decomposition of $C_3AH_6$. The immediate and earlier formation of $C_{12}A_7$ seemed to be accelerated by not only high surface area and instability of the thermally decomposed hydrate but also the catalytic effect of water decomposed from the hydrate. The final calcium monoaluminate clinker was very porous because of the influence of highly porous shape of the thermally decomposed hydrate.

• 한국방재학회 논문집
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• 제2권4호
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• pp.87-95
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• 2002

대도시의 인구 집중화 현상에 의해 1970년대 후반부터 다수의 민간 건축물이 시공되어 왔으며, 존치기간의 증가에 따라 그 구조 성능의 저하가 진행되고 있다. 이들은 현재 노후화가 진전되어 이에 대한 관리와 체계적 정비 계획이 필요한 시점에 이르렀다. 따라서 우리나라 대표적 대도시인 서울시를 중심으로 건축물의 현황 및 노후화 정도와의 상관관계를 정리 분석하고, 효율적인 관리와 체계적인 대책을 수립할 수 있는 근거자료를 제시하고자 한다. 본 연구는 서울시를 중심으로 한 건축물들의 분포 특성과 구조적 열화성상, 그리고 상관관계를 검토하였다 그 결과 구조 형식상 조적조 건축물이 우세하며, 강남에 비해 강북이 낮은 등급이 많은 것으로 나타났다. 또, 균열이 가장 큰 열화요인으로 발생 빈도도 70% 이상을 상회하고 있는 것으로 나타났으며, 구조 형식과 등급, 건물 유형과 등급의 상관관계 분석에서 각각 모두 서로 상관관계가 있는 것으로 나타났다. 따라서 강북 지역에 위치한 건축물들에 대한 구체적인 안전관리 방안과 대책이 필요하며 소규모 건축물에 대한 안전관리 방안도 필요한 것으로 보인다.